We report a very rare case of bone metastasis of the clavicle from collecting duct carcinoma.
A 28-year-old female had a growing tumor on the left clavicle. Resection biopsy was performed, and the first diagnosis was pigmented villonodular synovitis. She was refered to us. Examination revealed mild anemia (Hb10.6g/dl) and high ESR (85mm/h). Other serological examinations and urinalysis were normal. Tumor markers were within normal limits. Synovial sarcoma was suspected upon re-examination of the previously biopsied speciemen; however, the SYT-SSX gene was negative.
Despite chemotherapy and irradiation, the tumor rapidly doubled in size in 8 weeks. Marginal resection of the tumor including a part of the sternum, clavicle, and pleura was performed. Pathological diagnosis was malignant hemangioendothelioma.
Two months after surgery, bone metastasis at L3 was found. CT and MRI revealed a tumor at the left kidney. This tumor was resected and pathological diagnosis was collecting duct carcinoma, identical to the pathology of bone lesion of the clavicle.
